Orthogonal Frequency-Division Multiplexing (OFDM) is a well known multi-carrier modulation technique which can provide significant robustness to channel with long delay spreads at the cost of a loss in spectral efficiency. It has been adopted in many standards such as, for instance, IEEE 802.11a/n and the Digital Video Broadcasting for Terrestrial and Handheld (DVB-T/H). In OFDM, N complex symbols are transmitted in parallel so that each complex symbol modulates a single sub-carrier within the available bandwidth. The OFDM transmitter efficiently modulates all the N sub-carriers through an N-point inverse discrete Fourier transform (IDFT) efficiently implemented via a inverse fast Fourier transform (IFFT) algorithm. The output of the IDFT consists of N samples which are referred to as an OFDM symbol. The OFDM symbol is usually cyclically extended and transmitted over the air. The receiver matches the transmitter and, after the removal of the cyclic extension, performs a DFT to jointly demodulate all N sub-carriers. If the cyclic extension is at least as long as the maximum delay spread of the channel, if the channel is static during the duration of one OFDM symbol and if the receiver is perfectly synchronized to the transmitter, then the sub-carrier orthogonality is maintained at the receiver. Therefore, the data transmitted on each sub-carrier can be recovered with simple equalization algorithms. However, the receiver has to be synchronized with the transmitter both in frequency and time. The time synchronization in OFDM systems selects the block of samples to be processed by a receiver DFT. There is a significant amount of literature dealing with synchronization algorithms for OFDM systems. The most common methods use a cyclic extension to jointly detect the beginning of the OFDM symbol and correct the frequency offset. However, these methods are optimal only for non-frequency selective channels. In the presence of multipath channels, they only provide a coarse time synchronization which usually needs to be refined.